It should not be assumed that this medieval route exactly adhered to the line of its Roman forebear. A highway in use over such a long period would most likely have been subject to considerable detailed deviation in its course. The moorland stretches in the vicinity of the Golden Pots present a confusing multiplicity of trackways to the extent that it is difficult to determine the line of the original Roman route on the ground (pers. comm. A. Williams).
Evidence for a further significant deviation during the medieval or early modern eras can be traced south-east of Rochester between Horsley and Elishaw/Blakehope. On their respective maps neither Fryer (1820) nor Greenwood (1828) mark any trace of the former Roman road between Horsley and Blakehope. Instead only the Elsdon-Carter Fell turnpike road is shown in this stretch of the valley. Dere Street joined this route at Horsley and diverged from it at Elishaw to cross the river and rejoin its former course at Blakehope. Armstrong in 1769 presents a more complex picture. Dere Street is shown as passing through High Rochester-Bremenium fort, emerging from the south gate.
It then appears to resume its former course, passing to the east of Petty Knowes farm, continuing on until it reached Horsley where it crossed the road which ran from Elsdon along the length of the dale. Rather than continuing to follow the line of the Roman road straight on towards the river, Dere Street then apparently proceded through Bagraw and Birkhill, duplicating the valley track, which it rejoined at Birkhill before diverging again beside the ruins of the medieval settlement of Elishaw. Dere Street then crossed the Rede to resume its original course at Blakehope whilst the other route continued along the north side of the Rede passing through Otterburn to reach Elsdon and thence Newcastle, Morpeth or Corbridge.